ANALYTICAL SIMULATION OF PROGRESSIVE COLLAPSE OF PERIMETER FRAMES DUE TO OUT-OF-PLANE BEHAVIOR IN MOMENT FRAME STRUCTURES

Abstract

Typical steel moment-resisting frame structures in the United States, similar to many super-high-rise framed-tube structures being constructed in Japan, have stiff beams and columns only around perimeters and often have none or few seismic beams inside the building. The lack of strength and stiffness of connections between perimeter frames and floors to support the out-of-plane behavior of perimeter frames may cause unstable behavior when perimeter frames are separated from the floors due to accidental or earthquake loading. This study analytically simulates progressive collapse when the attachment of perimeter frames to floors is lost and predicts the strength of the connections required to prevent progressive collapse during earthquakes.